HP 40gs - Page 293

Step-by-Step Examples 16-19
Now press to see
the graphs.
Part 6 To find the values of and for
return to CAS, type each function in turn and press
. (You may need to press twice for further
simplification).
For example, pressing
X 0
gives the result at the right:
Likewise, pressing
X 3
gives this
answer at the right:
The other results are:
The slope of the tangents is .
We can find the values of for by
using the lim command.
xt() yt() t 0
π
3
---
2 π⋅
3
----------
π,, ,=
π
X
2π
3
------
⎝⎠
⎛⎞
1
4
---
=
X π()
3
2
---
=
Y 0() 0=
Y
π
3
---
⎝⎠
⎛⎞
3–
4
---------
-
=
Y
2π
3
------
⎝⎠
⎛⎞
33⋅–
4
-----------------
=
Y π() 0=
m
y' t()
x' t()
----------
=
y' t()
x' t()
----------
t 0
π
3
---
2 π⋅
3
----------
π,, ,=
hp40g+.book Page 19 Friday, December 9, 2005 12:27 AM